Occlusion has for long been recognized as a problem for some hearing aid users, and continuous efforts have been made to reduce the occlusion effect.
Known solutions to reduce the occlusion effect provide a vent in the earpiece or earmold in order to allow pressure equalization between the ear canal and the surroundings.
Further, active occlusion cancellation (AOC) systems have been developed, the AOC systems having a canal microphone in the ear canal and being arranged along with the receiver at the tip of the earmold.